Leonard andrews



No. 6|4,686. Patented Nov. 22, I898.

L. ANDREWS.

MAGNETIC GUT-OUT.

(Application filed Nov. 29, 1897.)

(No Model.)

m5 NORRIS PETERS $0.. PHOTO LIYHO-, WNSHIEGIDN, 0.1:.

UNITED STATES PATENT OFFICE.

LEONARD ANDREWS, OF HASTINGS, ENGLAND.

MAGNETIC CUT-OUT.

SPECIFICATION forming part of Letters Patent No. 614,686, dated November 22, 1898.

Application filed November 29, 1897. Serial No. 660,155. (No model.)

T0 at whom it may concern.-

Be it known that I, LEONARD ANDREWS, a subject of the Queen of GreatBritain, residing at 20 South Terrace, Hastings, county of Sussex, England, have invented certain new and useful Improvements in Magnetic Out- Outs, (patented in Great Britain, No. 17,395, August 6, 1896,) of which the following is a specification.

The object of this invention is to provide a reliable cut-out for disconnecting from the omnibus-bars any one of a series of electric generators working in parallel to supply current through a common system of mains in the event of the said generator becoming disabled through the failure of the exciting-current, a short circuit in the armature, or from any other cause which shall tend to render it unable to maintain its customary difference of potential at its terminals.

My invention and the manner of carrying same into practice will be fully understood upon referring to the accompanying diagram, which illustrates the principle of the winding and general arrangement of the connections.

As will be seen, the compound-wound solenoid A is connected up with the shunt B, wound half in one direction, as B, and half in the opposite direction, as B and the normal position of the core 0 is exactly in the center of the coil. Now suppose that the arrow-heads represent the direction of the current through all parts of the system at a particular moment when the machines on the bars are generating current. Then it will be seen that the direction of the current in the shunt-winding B of the solenoid A is opposite to that in the series D at the top half of said solenoid; but in the bottom half both of the currents are flowing in the same direction. The result is that the two windings neutralize each other at the top, but assist each other to produce a magnetic field at the bottom, the tendency of which is to hold the core 0 and catch F down and by this means to make it impossible for the cut-out operatingweightarm E to be released. Should, however, the generator become disabled, the direction of the shunt remains the same, but the series becomes reversed. The shunt-winding B now opposes the series inthe bottom half of the solenoid A, and B helps it in the top half, thus producing a magnetic field above the center of the solenoid A and causing the core 0 to spring up and lift the catch F supporting the weighted arm E, which, becoming released, falls with accelerating force upon the switch G, which is thus opened to disconnect the faulty machine from the general supply. The switch and weight can be reset by moving the lever H down to the dotted-line posi tiou.

The shunt-circuit maybe excited directly across the omnibus-bars G II or across the secondary of a transformer excited by the bars, as desired. It is obvious that the shuntcurrent by itself will not have any effect upon the core 0, because the two halves, being wound in opposite directions, will neutralize each other. Again, the series winding alone will tend to hold the core in the center of the coil; but as that is its normal position it will not be moved.

My invent-ion is equally applicable for use with continuous or with alternating current, because although in thelatter case the direction of the current in the series winding will be continually reversing the direction of the current in the shunt will reverse cophasally with it, and it is obvious thatthe position of the maximum field will only be changed when the direction of the series current is reversed relatively to the direction of the shunt-current.

\Vhen the cut-out is used with a continuous-current generator, the transformer between the cut-out and the bus-bars is omitted.

I have shown in conventional form two generators G and G both connected up to the bus-bars G H and each provided with a cut-out. Both of said generators may be of the type employed in generating alternating currents, in which case the shunt-circuits will be connected across the secondary of a transformer, which will be excited by a current from the bus-bars in the manner shown at the left hand of the said bars. hen a direct or a continuous current is used, however, both generators will be connected directly across the bus-bars without the intervention of transformers, as shown at the right hand of the bus-bars.

What I claim, and desire to secure by Let ters Patent, is

1. A magnetic cut-out for each of two or more electric-current generators, consisting of a core surrounded by a continuous windin gin series with the generator, a shunt-winding part of which is in the same direction as the series winding and the other part in the reverse direction, and a switch controlled by said core, substantially as described.

2. The combination with each one of a series of alternators of a cut-out consisting of a solenoid, having a winding in series with the generator, a shunt-winding connected directly across the secondary of a transformer the primary of which is connected across the bus-bars, said shunt having one part wound upon and in the same direction with part of the series winding and the other part wound upon but in a reverse direction to the other part of said series winding, and a switch controlled by said solenoid, substantially as described.

3. The combination with any one of a series of electric-current generators of a compound-wound magnetic device, such as a solenoid, the shunt-circuit of the latter being wound in opposite directions on the top and bottom thereof, a core normally held in the center of the solenoid, a catch connected to the core, a weighted arm normally held by said catch and a switch adapted to be opened by the fall of said arm when released, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

LEONARD ANDREYVS.

lVitnesses:

EDMUND S. SNEWIN, WILLIAM OswALn BROWN. 

